6,020 research outputs found

    Bandwidth EfïŹcient Root Nyquist Pulses for Optical Intensity Channels

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    Indoor diffuse optical intensity channels are bandwidth constrained due to the multiple reflected paths between the transmitter and the receiver which cause considerable inter-symbol interference (ISI). The transmitted signal amplitude is inherently non-negative, being a light intensity signal. All optical intensity root Nyquist pulses are time-limited to a single symbol interval which eliminates the possibility of finding bandlimited root Nyquist pulses. However, potential exists to design bandwidth efficient pulses. This paper investigates the modified hermite polynomial functions and prolate spheroidal wave functions as candidate waveforms for designing spectrally efficient optical pulses. These functions yield orthogonal pulses which have constant pulse duration irrespective of the order of the function, making them ideal for designing an ISI free pulse. Simulation results comparing the two pulses and challenges pertaining to their design and implementation are discussed

    Morphisms from P2 to Gr(2,C4)

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    In this note we study morphisms from P2 to Gr(2,C4) from the point of view of the cohomology class they represent in the Grassmannian. This leads to some new result about projection of d-uple imbedding of P2 to P5

    Assessment of Students Performances in Biology: Implication for Measurements and Evaluation of Learning

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    Scienceeducation is believed to be a vital tool for individual and societal development at large. The persistent low levels of students' achievement in sciences at the various public examinations in Nigeria have continued to draw the attention of major stakeholders in education. This study examined academic achievement of Senior Secondary School students in biology and gender difference in students' achievement was examined. Ex-post facto design of descriptive research was adopted for the study. A proforma was used to collect data from a sample of two hundred (200) students, selected using stratified random sampling procedure from the Science secondary schools in Kano state Nigeria. The data collected were the students' performances in biology achievement tests. The data were analysed using descriptive statistics and independent-sample t-test. Overall results showed that the test internal consistency reliability is low and unsatisfactory; the students performed below average (M=47.02, SD=16.493 (47%). Similarly, gender difference exists in biology performance with another significant difference between performance of urban and rural school students. The study concludes that, biology test used in Kano state qualifying examinations to assess students potential ability in biology is not a reliable measurement tool and that, academic performance of students in biology is unsatisfactory and evidence of differential performance between gender and schools locations. The implication for measurements and evaluation of learning as well as recommendations has been discussed

    Effectiveness of Pulmonary Rehabilitation in Patients with COPD

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    Background: Pulmonary rehabilitation (PR) is beneficial for patients with COPD, with improvement in exercise capacity and health-related quality of life. Despite these overall benefits, the responses to PR vary significantly among different individuals. It is not clear if PR is beneficial for patients with COPD and normal exercise capacity. Although it is believed that longer pulmonary rehabilitation programs can provide better results, most of the evidence comes from short-term programs. Objective: The objective of this analysis was to determine the effectiveness of respiratory services provided in the hospital or community by respiratory therapists (RTs) in reducing health care utilization and improving patient outcomes. The aim was to evaluate the outcomes of a comprehensive pulmonary rehabilitation (PR) in chronic obstructive pulmonary disease. Methodology: All 65 Pakistani patients who met the inclusion criteria with ages between 40 to 65 years, including both male and female, with mild to severe COPD were enrolled in the study on the basis of convenient sampling. Informed consent was taken from each patient starting about the study and their rights to withdraw from study. A demographics detail (name, age, sex) was noted along with the necessary medical history. A questionnaire was made to see the effects of pulmonary rehabilitation in patients with COPD. All necessary tests were performed to evaluate the patient betterment completely. Results: The mean FEV1 in the subjects was 1.29 ± 0.47 L/min, 64.8 ± 23.0% of predicted. Clinically there is a little effect on CXR pattern, FEV1 and FEV1/FVC after pulmonary rehabilitation. But overall quality of life improved after pulmonary rehabilitation. Mainly improvement occurs in peak expiratory flow rate, BORG dyspnea scale, 6 mint walk test distance (meters) and Oxygen saturation after rehabilitation. Conclusion: These results showed that patients with COPD had benefited from a comprehensive PR program in an out-patient setting regardless of disease severity. Exercise training can result in significant improvement in health-related quality of life, exercise capacity, respiratory muscle strength, and exertional dyspnea in subjects with COPD and normal exercise capacity

    Polyhexamethylene Biguanide and Nadifloxacin Self-Assembled Nanoparticles: Antimicrobial Effects against Intracellular Methicillin-Resistant Staphylococcus aureus

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    The treatment of skin and soft tissue infections caused by methicillin-resistant Staphylococcus aureus (MRSA) remains a challenge, partly due to localization of the bacteria inside the host’s cells, where antimicrobial penetration and efficacy is limited. We formulated the cationic polymer polyhexamethylene biguanide (PHMB) with the topical antibiotic nadifloxacin and tested the activities against intracellular MRSA in infected keratinocytes. The PHMB/nadifloxacin nanoparticles displayed a size of 291.3 ± 89.6 nm, polydispersity index of 0.35 ± 0.04, zeta potential of +20.2 ± 4.8 mV, and drug encapsulation efficiency of 58.25 ± 3.4%. The nanoparticles killed intracellular MRSA, and relative to free polymer or drugs used separately or together, the nanoparticles displayed reduced toxicity and improved host cell recovery. Together, these findings show that PHMB/nadifloxacin nanoparticles are effective against intracellular bacteria and could be further developed for the treatment of skin and soft tissue infections

    Nonlinear wavelength selection in surface faceting under electromigration

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    We report on the control of the faceting of crystal surfaces by means of surface electromigration. When electromigration reinforces the faceting instability, we find perpetual coarsening with a wavelength increasing as t1/2t^{1/2}. For strongly stabilizing electromigration, the surface is stable. For weakly stabilizing electromigration, a cellular pattern is obtained, with a nonlinearly selected wavelength. The selection mechanism is not caused by an instability of steady-states, as suggested by previous works in the literature. Instead, the dynamics is found to exhibit coarsening {\it before} reaching a continuous family of stable non-equilibrium steady-states.Comment: 5 pages, 4 figures, submitte

    Practical Wisdom: A Review of Foundations of Ethical Practice, Research, and Teaching in Psychology and Counseling

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    In Karen Strohm Kitchener and Sharon K. Anderson’s Foundations of Ethical Practice, Research, and Teaching in Psychology and Counseling (2011) they use the term practical wisdom or prudence as a way to make right decisions in real life situation. The authors lay the foundation for conceptually dealing with ethical problems for psychologists, counselors, students, and trainees. The book is in two parts. In the first six chapters, the authors focus on the foundations of ethical reasoning. The next part focuses on the ethical issues psychologists and counselors are confronted with in their roles

    A Journey into the Lived Experience: A Review of Janet Salmon\u27s Qualitative Online Interviews Strategies, Design, and Skills

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    In Janet Salmons Qualitative Online Interviews (2014) she provides researchers with the tools to be innovative in their research interviews. Researchers will have the skills to conduct a qualitative research study using technology. For the purpose of this book she changes the term online research to information and communications technologies (ICTs). Salmons’ uses an EInterview Research Framework, which includes eight categories of questions and designs

    The Duffy Blood Group System

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    The Duffy group system includes six known antigens that reside on a glycoprotein which acts as a receptor for chemokines. It is also a receptor for some malaria species. There are significant racial variations in expression of Duffy antigens. Approximately 68% of Blacks lack both Fya and Fyb antigens. Individuals with this unique phenotype are resistant to two malaria species. Antibodies formed against the Duffy antigens are of IgG subclass and are clinically significant as they can be implicated in acute and delayed hemolytic transfusion reactions as well as hemolytic disease of fetus and newborn. Patients who form anti-Fya or anti-Fyb must receive antigen negative blood units in the future

    On Hamilton cycle decompositions of complete multipartite graphs which are both cyclic and symmetric

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    Let G be a graph with v vertices. A Hamilton cycle of a graph is a collection of edges which create a cycle using every vertex. A Hamilton cycle decomposition is cyclic if the set of cycle is invariant under a full length permutation of the vertex set. We say a decomposition is symmetric if all the cycles are invariant under an appropriate power of the full length permutation. Such decompositions are known to exist for complete graphs and families of other graphs. In this work, we show the existence of cyclic n-symmetric Hamilton cycle decompositions of a family of graphs, the complete multipartite graph Km×n where the number of parts, m, is odd and the part size, n, is also odd. We classify the existence where m is prime and prove the existence in additional cases where m is a composite odd integer
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